Unload debugger when message handler is cleared

src/debug.h

 // Copyright 2006-2008 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 611 matching lines @@
   static void StopAgent();
 
   // Unload the debugger if possible. Only called when no debugger is currently
   // active.
   static void UnloadDebugger();
 
   inline static bool EventActive(v8::DebugEvent event) {
     ScopedLock with(debugger_access_);
 
     // Check whether the message handler was been cleared.
-    if (message_handler_cleared_) {
+    if (debugger_unload_pending_) {
       UnloadDebugger();
     }
 
     // Currently argument event is not used.
     return !compiling_natives_ && Debugger::IsDebuggerActive();
   }
 
   static void set_compiling_natives(bool compiling_natives) {
     Debugger::compiling_natives_ = compiling_natives;
   }
   static bool compiling_natives() { return Debugger::compiling_natives_; }
   static void set_loading_debugger(bool v) { is_loading_debugger_ = v; }
   static bool is_loading_debugger() { return Debugger::is_loading_debugger_; }
 
  private:
   static bool IsDebuggerActive();
+  static void ListenersChanged();
 
   static Mutex* debugger_access_;  // Mutex guarding debugger variables.
   static Handle<Object> event_listener_;  // Global handle to listener.
   static Handle<Object> event_listener_data_;
   static bool compiling_natives_;  // Are we compiling natives?
   static bool is_loading_debugger_;  // Are we loading the debugger?
   static bool never_unload_debugger_;  // Can we unload the debugger?
   static v8::Debug::MessageHandler2 message_handler_;
-  static bool message_handler_cleared_;  // Was message handler cleared?
+  static bool debugger_unload_pending_;  // Was message handler cleared?
   static v8::Debug::HostDispatchHandler host_dispatch_handler_;
   static int host_dispatch_micros_;
 
   static DebuggerAgent* agent_;
 
   static const int kQueueInitialSize = 4;
   static LockingCommandMessageQueue command_queue_;
   static Semaphore* command_received_;  // Signaled for each command received.
 
   friend class EnterDebugger;
@@ skipping 149 matching lines @@
   Debug::AddressId id_;
   int reg_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_DEBUGGER_SUPPORT
 
 #endif  // V8_DEBUG_H_